The goalkeeper is expected to attract offers from Europe’s biggest clubs at the end of the season.

Courtois, 23, has three years remaining on the contract he signed in 2014 but he will be targeted if Chelsea fail to turn around what has been a wretched season.

A Chelsea source has told Football Insider that the club are concerned that Courtois could be the subject of interest from rival clubs.

The Londoners are still in the Champions League and the FA Cup but they face a pivotal few weeks which could end their hunt for trophies in 2015/16.

Courtois is one of the few players in Guus Hiddink’s squad whose reputation has not been diminished by a wretched campaign that has left the champions well adrift of the Premier League pace-setters.

The only realistic chance Chelsea have of qualifying for next season’s Champions League is to win the competition this season, but they must overturn a 2-1 deficit from the first leg of Tuesday’s last-16 first leg clash against runaway leaders Paris Saint-Germain.

Courtois, who joined Chelsea for £5million in 2011 before spending three seasons on loan at Atletico Madrid, has made 19 appearances for the club in a season disrupted by a serious knee injury and has continued to enhance his reputation as one of Europe’s outstanding goalkeepers.